Various methods of molding hollow plastic articles and/or containers are well known in the prior art. Plastic containers have found substantial increasing applications; however, despite their weight and toughness, their use is restricted by the cost and characteristic of the plastic composition, particularly for storage of products which will deteriorate or be contaminated, inter alia, by water, carbon dioxide, oxygen and the like.
Recently a process has been advanced which produces a barrier container, i.e., a semi-rigid plastic container provided with a liner or inner layer of another material having properties different than the other layer thereof. In accordance with such process, a preformed liner or sleeve (manufactured, for example, by thermoforming techniques) is positioned over a core rod with a parison being subsequently formed about the liner in an injection station of an injection blow molding machine. The line parison is thereafter expanded in a blow molding station of the machine with the resulting lined container being removed from the core rod in a product receiving station.
In the aforementioned copending application there is disclosed a liner feeder assembly comprised of a liner supply assembly and the transfer assembly including a liner block having at least one cavity for receiving a preformed liner. The liner transfer assembly is provided with a pump and valve assembly in fluid communication with each such cavity for alternately placing such cavity in fluid communications with the suction side or the compression side of the pump for removing a liner from the liner supply assembly containing a supply of nestable liners and for the subsequent placing of the liner on a core rod or pin. At high speed operation, it is necessary to ensure for the positive removal successively of a single liner from a stack thereof to permit continuous operation over extended periods of time.